Message exchanges between two or more parties in a wireless network or over the Internet are vulnerable to eavesdropping and manipulation by other parties. Security is required to protect the confidentiality and integrity of the message exchanges. Typically, messages are protected through encrypting and authenticating the messages with a shared session key, as referred to as pairwise temporal key (PTK) hereinafter, between the intended parties. A shared session key is often derived from a shared master key that is rarely used and tightly guarded against potential compromise.
As its name implies, a session key or a temporal key is typically used for a limited period of time, such as during a single communications session between two devices. Accordingly, a new session key is typically generated for each new communication session between the devices. It is important that the session key can be generated quickly and with minimum computations so that each communication session can be easily established.
Existing session key computation methods require involved message formatting and computation to generate the session key and the confirmation key and key message authentication codes (KMAC) that are used during the session key generation procedure. Therefore, a procedure for computing session keys that minimizes the required formatting and computation yet still provides adequate security strength is needed.